Conventional cleaning and disinfection techniques eliminate the risk of endoscopic transmission of Helicobacter pylori

Abstract

Objective: To determine whether endoscopes serve as a reservoir for Helicobacter pylori and whether two commonly used cleaning and disinfection methods eliminate the risk of H. pylori transmission.

Methods: A prospective study was carried out in 107 patients who were undergoing upper gastrointestinal endoscopy for routine clinical indications. H. pylori DNA was assayed by polymerase chain reaction (PCR) of endoscope washes before and after procedure, in gastric aspirates and in endoscope washes after cleaning and disinfection of endoscopes. Gastric biopsies were assayed by rapid urease test (CLOtest, Tri-Med Specialties Inc., Lenexa, KS) of two antral biopsies.

Results: Forty-one of 107 (38%) patients were H. pylori-positive by PCR. Endoscopes were contaminated after 25 of 41 (61%) H. pylori-positive procedures. However, 107 of 107 pre-endoscopy and postcleaning aspirates were negative, indicating that decontamination was 100% effective. The urease test was positive in 25 of 41 H. pylori-positive patients, a sensitivity of 61%. PCR was positive in 41 of 41 H. pylori-positive patients, a sensitivity of 100%. In 5 of 16 PCR-positive/urease-negative patients, the identification of H. pylori was clinically relevant.

Conclusion: Endoscopes are frequently contaminated with H. pylori after endoscopy in H. pylori-infected patients, but conventional cleaning and disinfection techniques are highly effective in eliminating H. pylori. When appropriate negative control samples are obtained from the endoscope, PCR of endoscopic gastric aspirates appears to be a sensitive test that can detect clinically relevant H. pylori infection that is missed when only a rapid urease test is used.